Wireless docking stations, or wireless docking systems, are used to wirelessly connect a mobile device to a set of peripherals, through a concentrator known as a docking station, in the user work environment. These peripherals typically include monitors, pointing devices (e.g. mice), keyboards, cameras, storage device, computers, projectors, music players, video players, speakers, and the like.
Providing an acceptable docking experience with wire-like quality requires a minimum bandwidth level available at the wireless link. When the available bandwidth at the wireless link is below this minimum value, the wireless docking experience is not acceptable to the typical user. For example, the quality of the image at the dock monitor will be below what the user finds acceptable. To avoid this, wireless docking systems implement a function known as admission and drop control, whereby the wireless docking session is not initiated until the minimum bandwidth level required is available at the wireless link, and the session is dropped when this bandwidth is no longer available. The admission and drop control function constantly monitors the link quality to estimate the available bandwidth and make a decision on whether to initiate or drop the wireless docking session. The set of locations where the link is such that the required bandwidth for admission is available is known as the admission range. The set of locations where the link is such that the required bandwidth for retention to the wireless docking session is available is known as the retention range.
Required bandwidth for admission and drop may not be the same, due to several reasons. For example, the admission decision might include a safety margin to avoid an undesirable scenario where shortly after admission the link conditions worsen and the session is dropped. For simplicity, in what follows, this distinction will be ignored and admission and retention range will be assumed to be identical and referred to as admission range.
Wireless docking systems support a mode where the user automatically connects to the dock whenever he enters admission range. This mode is required to allow a fully seamless docking experience where the user does not need to open an application in the mobile device (i.e. the client), or even open the device lid where relevant in order to initiate a wireless docking session. This mode is known as autoconnect and is expected to be the preferred connection mode of most users.
Depending on the propagation characteristics of the environment, the admission range may be much larger than the physical size of the user working area (office or cubicle). For example, the admission range may be as large as 10 meters (m) from the dock, while a typical cubicle size is 2 m by 2 m. In such a case, in the autoconnect mode, the user may connect to the docking station when well outside his working area. This presents a privacy issue, as the user screen is projected on the dock monitor when the user is not physically inside his working environment and other people may have access to the user's private information.
A possible solution to this privacy problem would be to increase the minimum bandwidth level requested for admission and retention in order to artificially decrease the admission range. The problem with this solution is that it also decreases the system coverage within the working environment, e.g. in locations where the line of sight to the dock is blocked. This is because the spatial directivity of the radiation together with specific orientation of the platform, or presence of obstacles, may result in equivalent link conditions in such situations that are completely different from user perspective. For example, a client 0.5 m away from the dock on the same cubicle might experience similar link conditions as a client 10 m away from the dock in a different cubicle. Therefore, decreasing the admission range to avoid unintended automatic connection to a dock 10 m away might also prevent intended automatic connection to a dock 0.5 m away.